Best way to compare nested dictionaries in a list, Python-CodePudding

I'm querying a public endpoint to get an exchange rate of varies exchanges that returns a list with nested dictionaries. I'm most interesting in is the key "amount" field in the nested dictionaries. I'm struggling to come up with a solution to store the nested dictionary that has the most "amount" value in a variable. Any ideas would be extremely helpful. I'm banging my head against the wall on this one.

Here is the list:

list_with_nested_dicts = [{"partner":"simpleswap","amount":0,"currency":"cel","supportRate":3,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"simpleswap","amount":0,"currency":"cel","supportRate":3,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"stealthex","amount":37.90346104,"currency":"cel","supportRate":2,"duration":66.62083333333334,"fixed":true,"min":39.91443225,"max":2550.215226,"exists":true,"id":""},{"partner":"stealthex","amount":37.20972396,"currency":"cel","supportRate":2,"duration":23.158333333333335,"fixed":false,"min":77.82938688,"max":25209.49720665,"exists":true,"id":""},{"partner":"godex","amount":0,"currency":"cel","supportRate":0,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"changenow","amount":37.2077365,"currency":"cel","supportRate":2,"duration":11.08859649122807,"fixed":false,"min":56.60646516,"max":25259.88795509,"exists":true,"id":""},{"partner":"changelly","amount":0,"currency":"cel","supportRate":1,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"changelly","amount":0,"currency":"cel","supportRate":1,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"instaswap","amount":0,"currency":"cel","supportRate":2,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"exolix","amount":0,"currency":"cel","supportRate":0,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"fixedfloat","amount":0,"currency":"cel","supportRate":3,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"switchain","amount":0,"currency":"cel","supportRate":2,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"changehero","amount":0,"currency":"cel","supportRate":3,"duration":56.41111111111111,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"changehero","amount":0,"currency":"cel","supportRate":3,"duration":2.4833333333333334,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"binance","amount":0,"currency":"cel","supportRate":2,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"nexchange","amount":0,"currency":"cel","supportRate":3,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"letsexchange","amount":0,"currency":"cel","supportRate":2,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""},{"partner":"letsexchange","amount":0,"currency":"cel","supportRate":2,"duration":0,"fixed":false,"min":0,"max":0,"exists":false,"id":""},{"partner":"alfacash","amount":0,"currency":"cel","supportRate":3,"duration":0,"fixed":true,"min":0,"max":0,"exists":false,"id":""}]

The dictionary that has the most amount is:

{"partner":"stealthex","amount":37.90346104,"currency":"cel","supportRate":2,"duration":66.62083333333334,"fixed":true,"min":39.91443225,"max":2550.215226,"exists":true,"id":""}

CodePudding user response：

Use the key parameter of max:

from operator import  itemgetter
res = max(list_with_nested_dicts, key=itemgetter("amount"))
print(res)

Output

{'partner': 'stealthex', 'amount': 37.90346104, 'currency': 'cel', 'supportRate': 2, 'duration': 66.62083333333334, 'fixed': True, 'min': 39.91443225, 'max': 2550.215226, 'exists': True, 'id': ''}

From the documentation:

The key argument specifies a one-argument ordering function like that used for list.sort()

Note there is no need to use operator.itemgetter, you could simply use a lambda function as the value of key:

max(list_with_nested_dicts, key=lambda x: x["amount"])

CodePudding user response：

Your dict is not a valid python expression, e.g., true is not defined (unless you have defined it before). You might want to replace true with True and false with False.

You can use max with key parameter:

from operator import itemgetter
d = max(list_with_nested_dicts, key=itemgetter('amount'))
print(d) # 083333333334, 'fixed': True, 'min': 39.91443225, 'max': 2550.215226, 'exists': True, 'id': ''}

CodePudding user response：

Try this: Bu you will need to replace 'true' with True and 'false' with 'False' for this code to work.

list_with_nested_dicts.sort(key=lambda a: a['amount'])
print(list_with_nested_dicts[-1])